Absorption of bovine colostral immunoglobulins G and M in newborn foals.

The research article discusses an investigation into how newborn foals absorb IgG and IgM immunoglobulins from bovine colostrum, comparing these to foals feeding from their mothers. The study finds that both groups show similar maximal concentration of IgG, with a varying rate of endogenous synthesis of IgG and IgM.

Research Method

• Researchers selected 12 newborn foals for their study. One group of six foals was administered bovine colostrum (principal foals), while the second group was allowed to suckle from their mothers (control foals).
• The principal foals were given 400 ml of bovine colostrum at two-hour intervals for 20 hours starting two hours after foaling. This colostrum contained high amounts of IgG and IgM.
• From birth until 98 days old, the concentration of IgG and IgM in the foals’ serum was determined using single radial immunodiffusion, a method used to measure antigen-antibody reactions.

Results

• At birth, no detectable equine IgG was found in principal foals, but one control foal exhibited serum equine IgG at a concentration of 185 mg/dl.
• Post-colostrum ingestion, the maximum serum bovine IgG concentration in principal foals was within a range of 1,350 to 3,300 mg/dl. The maximum serum equine IgG concentration in control foals was within the range of 500 to 6,000 mg/dl.
• The calculated biological half-life of bovine and equine IgG was respectively 9.4 and 26 days in the principal and control groups.
• Endogenous synthesis of IgG was detected first at three days of age in one principal foal, but in the other principal foals, it was detected between 28 and 42 days. From the 56th day, no significant difference in serum equine IgG concentration was observed between the groups.
• At foaling, both groups had low concentrations of equine IgM. However, in control foals, there were marked variations in the increase in equine IgM concentration after ingesting colostrum.

Conclusion

The findings show no significant deviation in the pattern of IgG absorption between foals fed bovine colostrum and those suckling their mothers. However, the rate of endogenous synthesis of IgG and IgM varied, implying a difference in the establishment of the foals’ active immune system depending on the colostrum source. These findings could guide future practices for rearing foals, particularly in situations where the mother is unable to nurse.